In 2016, Waterway sold 1000 units at $500 each, and earned net income of $40000. Variable expenses were $200 per unit, and fixed expenses were $250000. The same selling price is expected for 2017. Waterways variable cost per unit will rise by 10% in 2017 due to increasing material costs, so they are tentatively planning to cut fixed costs by $10000. How many units must Waterway sell in 2017 to maintain the same income level as 2016?